RFR (XS) 8221307 : String.substring() OOB exception on start index reports improper information

[Ivan Gerasimov]

Hi Claes!

On 8/8/19 6:56 AM, Claes Redestad wrote:
> Hi,
>
> perhaps a stupid question, but why isn't String::substring(int) 
> calling substring(beginIndex, length())? That'd ensure consistent error
> messages, but otherwise preserve semantics.
>
It's a good point, actually!

I suspect that originally substring(int) had a separate implementation 
for performance reason.

I agree, it would make most sense to implement one via another unless 
there's a performance penalty.

Let me do some measurements, and then I'll report back.

With kind regards,

Ivan


> /Claes
>
> On 2019-08-08 02:17, Ivan Gerasimov wrote:
>> Hello!
>>
>> The exception thrown by substring(int) may look confusing.
>> For example it produces "String index out of range: -1" when the 
>> index is length+1.
>>
>> It is proposed to make the error message more clear, similar to what 
>> we have for substring(int, int).
>>
>> BUGURL: https://bugs.openjdk.java.net/browse/JDK-8221307
>> WEBREV: http://cr.openjdk.java.net/~igerasim/8221307/00/webrev/
>>
>> Would you please help review?
>>
>
-- 
With kind regards,
Ivan Gerasimov